Remove IJobHistory

[nulltoken]

Pull request description

Currently, JobExecutor feeds a NoOpHistory, registered in the DI container by AddNCronJob().

The IJobHistory interface being internal, this registration can't be later replaced with a custom concrete type by users of the library with knowledge of its internal implementation.

The README explicitly states "There is no history of jobs that have been run."

This cleans the codebase from a section of useless code.

However, would this be a stepping stone for a feature to come, feel free to ignore this code change proposal and close this PR.

PR meta checklist

• [X] Pull request is targeted at main branch for code
• [ ] Pull request is linked to all related issues, if any.

Code PR specific checklist

• [ ] My code follows the code style of this project and AspNetCore coding guidelines.
• [ ] My change requires a change to the documentation.
  • [ ] I have updated the documentation accordingly.
• [ ] I have updated the appropriate sub section in the CHANGELOG.md.
• [ ] I have added, updated or removed tests to according to my changes.
  • [X] All tests passed.

[linkdotnet]

The idea was to build a system for the Dashboard (or something which lets you look inside the state). It is for the better that we remove this. Not sure if I would need this if we tackle that feature.

So thanks for the good work @nulltoken